The 64-bit AIX Virtual Memory Model

The 64-bit model allows many more segments, although each segment is still 256 MB.

Again, the address space is managed at segment level, but the granularity of function for each segment is much finer.

With the large address space available to the 64-bit process, you are unlikely to encounter the same kind of problems with relation to native heap usage as described later in this section, although you might still suffer from a leak in the native heap.